Wrench.



. PATENTEDIABR.16,1907. 0. D BRADSTREET.

WRENCH. APPLICATION r1231) 00T.18, 1900.

' IN VENTOR,

W] TNESSES;

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CECIL D. BRADSTREET, OF SAN FRANCISCO, CALIFORNIA.

WRENCH.

Specification of Letters Patent.

' Patented April 16,1907.

Application filed October 13,1906. Serial No. 338,788.

To a whom it may concern:

Be it known that I, CECIL D. BRADSTREET, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented new and useful Improvements in Wrenches, of which the following is a specification.

This invention relates to an improvement in the wrench known as the Stilson wrench, which is now extensively in use. The weakest portion of these wrenches and the part where breakages frequently occur is in the stem of the movable jaw at the point Where it bears against its guide. It has heretofore been considered impracticable to strengthen the wrench at this point without increasing the diameter of the nut, which, again, means an increase ofthe guide and practically an enlargement of almost the whole Wrench. The difficulty in thickening the stem without increasing the nut lies in the fact that a certain amount of flat bearingsurface must be given to the stand to prevent the jaw turning, and if the stem is thickened this bearing-surface is unduly reduced in extent, so that there is a liability of the movable jaw to turn. I have, however, devised a construction by which this stem can be strengthened without reducing the extent of the bearing-surface.

In the accompanying drawings, Figure 1 is a side elevation of my improved wrench. Fig. 2 is a rear view thereof. Fig. 3 is a section on the line 3 3 of Fig. 1. Fig. 4 is a section on the line 4 4 of Fig. 1. Fig. 5 is a section on the line 5 5 of Fig. 1.

Referring to the drawings, 1 indicates the fixed jaw with handle 11, and 2 the movable jaw, having a threaded stem 3 received within a nut 4, said nut being contained in a socket in a guideway '5, pivoted at 6 to the fixed jaw and controlled by springs 7 and 8, all of the usual construction.

In my improvement the stem 3 of the movable jaw is formed on each of its unthreaded sides with an approximately halfround rib 9, and the guideway 5 is formed with correspondingly-rounded channels 10 to receive said ribs. This construction is permitted by reason of the spaceintervening within the ring or nut 4 on each of the unthreaded sides of the stem 3, permitting of the addition of these ribs to strengthen said stem, while the construction is such that the bearing-surfaces at the sides of the stem, preventing the turning of the same, are not materially diminished. In other words, the objection heretofore found to the frequent breaking of the movable jaw is avoided without introducing any defects or disadvantages or materially increasing the dimensions of the other parts.

I claim A wrench of the character described having a fixed jaw, a movable jaw having a threaded stem, a nut for said stem, a guide receiving said nut and pivoted to the fixed jaw, and springs controlling said guide, the stem of the movable jaw having on each side a longitudinal reinforcing-rib, and the guideway being suitably conformed to fit closely around said ribs, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing Witnesses.

C. D. BRADSTREET.

Witnesses:

F. M. WRIGHT, B. NAGGS. 

